/* Miscellaneous test program support routines.

Copyright 2000, 2001, 2002, 2003, 2005, 2013 Free Software Foundation, Inc.

This file is part of the GNU MP Library test suite.

The GNU MP Library test suite is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 3 of the License,
or (at your option) any later version.

The GNU MP Library test suite is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
Public License for more details.

You should have received a copy of the GNU General Public License along with
the GNU MP Library test suite.  If not, see http://www.gnu.org/licenses/.  */

#include "config.h"

#include <ctype.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>     /* for getenv */
#include <string.h>

#if HAVE_FLOAT_H
#include <float.h>      /* for DBL_MANT_DIG */
#endif

#if TIME_WITH_SYS_TIME
# include <sys/time.h>  /* for struct timeval */
# include <time.h>
#else
# if HAVE_SYS_TIME_H
#  include <sys/time.h>
# else
#  include <time.h>
# endif
#endif

#include "gmp.h"
#include "gmp-impl.h"
#include "tests.h"


/* The various tests setups and final checks, collected up together. */
void
tests_start (void)
{
  /* don't buffer, so output is not lost if a test causes a segv etc */
  setbuf (stdout, NULL);
  setbuf (stderr, NULL);

  tests_memory_start ();
  tests_rand_start ();
}
void
tests_end (void)
{
  tests_rand_end ();
  tests_memory_end ();
}


void
tests_rand_start (void)
{
  gmp_randstate_ptr  rands;
  char           *perform_seed;
  unsigned long  seed;

  if (__gmp_rands_initialized)
    {
      printf ("Please let tests_start() initialize the global __gmp_rands.\n");
      printf ("ie. ensure that function is called before the first use of RANDS.\n");
      abort ();
    }

  gmp_randinit_default (__gmp_rands);
  __gmp_rands_initialized = 1;
  rands = __gmp_rands;

  perform_seed = getenv ("GMP_CHECK_RANDOMIZE");
  if (perform_seed != NULL)
    {
#ifdef HAVE_STRTOUL
      seed = strtoul (perform_seed, 0, 0);
#else
      /* This will not work right for seeds >= 2^31 on 64-bit machines.
	 Perhaps use atol unconditionally?  Is that ubiquitous?  */
      seed = atoi (perform_seed);
#endif
      if (! (seed == 0 || seed == 1))
        {
          printf ("Re-seeding with GMP_CHECK_RANDOMIZE=%lu\n", seed);
          gmp_randseed_ui (rands, seed);
        }
      else
        {
#if HAVE_GETTIMEOFDAY
          struct timeval  tv;
          gettimeofday (&tv, NULL);
          seed = tv.tv_sec ^ (tv.tv_usec << 12);
	  seed &= 0xffffffff;
#else
          time_t  tv;
          time (&tv);
          seed = tv;
#endif
          gmp_randseed_ui (rands, seed);
          printf ("Seed GMP_CHECK_RANDOMIZE=%lu (include this in bug reports)\n", seed);
        }
      fflush (stdout);
    }
}
void
tests_rand_end (void)
{
  RANDS_CLEAR ();
}


/* Only used if CPU calling conventions checking is available. */
mp_limb_t (*calling_conventions_function) (ANYARGS);


/* Return p advanced to the next multiple of "align" bytes.  "align" must be
   a power of 2.  Care is taken not to assume sizeof(int)==sizeof(pointer).
   Using "unsigned long" avoids a warning on hpux.  */
void *
align_pointer (void *p, size_t align)
{
  gmp_intptr_t d;
  d = ((gmp_intptr_t) p) & (align-1);
  d = (d != 0 ? align-d : 0);
  return (void *) (((char *) p) + d);
}


/* Note that memory allocated with this function can never be freed, because
   the start address of the block allocated is lost. */
void *
__gmp_allocate_func_aligned (size_t bytes, size_t align)
{
  return align_pointer ((*__gmp_allocate_func) (bytes + align-1), align);
}


void *
__gmp_allocate_or_reallocate (void *ptr, size_t oldsize, size_t newsize)
{
  if (ptr == NULL)
    return (*__gmp_allocate_func) (newsize);
  else
    return (*__gmp_reallocate_func) (ptr, oldsize, newsize);
}

char *
__gmp_allocate_strdup (const char *s)
{
  size_t  len;
  char    *t;
  len = strlen (s);
  t = (char *) (*__gmp_allocate_func) (len+1);
  memcpy (t, s, len+1);
  return t;
}


char *
strtoupper (char *s_orig)
{
  char  *s;
  for (s = s_orig; *s != '\0'; s++)
    if (isascii (*s))
      *s = toupper (*s);
  return s_orig;
}


void
mpz_set_n (mpz_ptr z, mp_srcptr p, mp_size_t size)
{
  ASSERT (size >= 0);
  MPN_NORMALIZE (p, size);
  MPZ_REALLOC (z, size);
  MPN_COPY (PTR(z), p, size);
  SIZ(z) = size;
}

void
mpz_init_set_n (mpz_ptr z, mp_srcptr p, mp_size_t size)
{
  ASSERT (size >= 0);

  MPN_NORMALIZE (p, size);
  ALLOC(z) = MAX (size, 1);
  PTR(z) = __GMP_ALLOCATE_FUNC_LIMBS (ALLOC(z));
  SIZ(z) = size;
  MPN_COPY (PTR(z), p, size);
}


/* Find least significant limb position where p1,size and p2,size differ.  */
mp_size_t
mpn_diff_lowest (mp_srcptr p1, mp_srcptr p2, mp_size_t size)
{
  mp_size_t  i;

  for (i = 0; i < size; i++)
    if (p1[i] != p2[i])
      return i;

  /* no differences */
  return -1;
}


/* Find most significant limb position where p1,size and p2,size differ.  */
mp_size_t
mpn_diff_highest (mp_srcptr p1, mp_srcptr p2, mp_size_t size)
{
  mp_size_t  i;

  for (i = size-1; i >= 0; i--)
    if (p1[i] != p2[i])
      return i;

  /* no differences */
  return -1;
}


/* Find least significant byte position where p1,size and p2,size differ.  */
mp_size_t
byte_diff_lowest (const void *p1, const void *p2, mp_size_t size)
{
  mp_size_t  i;

  for (i = 0; i < size; i++)
    if (((const char *) p1)[i] != ((const char *) p2)[i])
      return i;

  /* no differences */
  return -1;
}


/* Find most significant limb position where p1,size and p2,size differ.  */
mp_size_t
byte_diff_highest (const void *p1, const void *p2, mp_size_t size)
{
  mp_size_t  i;

  for (i = size-1; i >= 0; i--)
    if (((const char *) p1)[i] != ((const char *) p2)[i])
      return i;

  /* no differences */
  return -1;
}


void
mpz_set_str_or_abort (mpz_ptr z, const char *str, int base)
{
  if (mpz_set_str (z, str, base) != 0)
    {
      fprintf (stderr, "ERROR: mpz_set_str failed\n");
      fprintf (stderr, "   str  = \"%s\"\n", str);
      fprintf (stderr, "   base = %d\n", base);
      abort();
    }
}

void
mpq_set_str_or_abort (mpq_ptr q, const char *str, int base)
{
  if (mpq_set_str (q, str, base) != 0)
    {
      fprintf (stderr, "ERROR: mpq_set_str failed\n");
      fprintf (stderr, "   str  = \"%s\"\n", str);
      fprintf (stderr, "   base = %d\n", base);
      abort();
    }
}

void
mpf_set_str_or_abort (mpf_ptr f, const char *str, int base)
{
  if (mpf_set_str (f, str, base) != 0)
    {
      fprintf (stderr, "ERROR mpf_set_str failed\n");
      fprintf (stderr, "   str  = \"%s\"\n", str);
      fprintf (stderr, "   base = %d\n", base);
      abort();
    }
}


/* Whether the absolute value of z is a power of 2. */
int
mpz_pow2abs_p (mpz_srcptr z)
{
  mp_size_t  size, i;
  mp_srcptr  ptr;

  size = SIZ (z);
  if (size == 0)
    return 0;  /* zero is not a power of 2 */
  size = ABS (size);

  ptr = PTR (z);
  for (i = 0; i < size-1; i++)
    if (ptr[i] != 0)
      return 0;  /* non-zero low limb means not a power of 2 */

  return POW2_P (ptr[i]);  /* high limb power of 2 */
}


/* Exponentially distributed between 0 and 2^nbits-1, meaning the number of
   bits in the result is uniformly distributed between 0 and nbits-1.

   FIXME: This is not a proper exponential distribution, since the
   probability function will have a stepped shape due to using a uniform
   distribution after choosing how many bits.  */

void
mpz_erandomb (mpz_ptr rop, gmp_randstate_t rstate, unsigned long nbits)
{
  mpz_urandomb (rop, rstate, gmp_urandomm_ui (rstate, nbits));
}

void
mpz_erandomb_nonzero (mpz_ptr rop, gmp_randstate_t rstate, unsigned long nbits)
{
  mpz_erandomb (rop, rstate, nbits);
  if (mpz_sgn (rop) == 0)
    mpz_set_ui (rop, 1L);
}

void
mpz_errandomb (mpz_ptr rop, gmp_randstate_t rstate, unsigned long nbits)
{
  mpz_rrandomb (rop, rstate, gmp_urandomm_ui (rstate, nbits));
}

void
mpz_errandomb_nonzero (mpz_ptr rop, gmp_randstate_t rstate, unsigned long nbits)
{
  mpz_errandomb (rop, rstate, nbits);
  if (mpz_sgn (rop) == 0)
    mpz_set_ui (rop, 1L);
}

void
mpz_negrandom (mpz_ptr rop, gmp_randstate_t rstate)
{
  mp_limb_t  n;
  _gmp_rand (&n, rstate, 1);
  if (n != 0)
    mpz_neg (rop, rop);
}

mp_limb_t
urandom (void)
{
#if GMP_NAIL_BITS == 0
  mp_limb_t  n;
  _gmp_rand (&n, RANDS, GMP_LIMB_BITS);
  return n;
#else
  mp_limb_t n[2];
  _gmp_rand (n, RANDS, GMP_LIMB_BITS);
  return n[0] + (n[1] << GMP_NUMB_BITS);
#endif
}


/* Call (*func)() with various random number generators. */
void
call_rand_algs (void (*func) (const char *, gmp_randstate_ptr))
{
  gmp_randstate_t  rstate;
  mpz_t            a;

  mpz_init (a);

  gmp_randinit_default (rstate);
  (*func) ("gmp_randinit_default", rstate);
  gmp_randclear (rstate);

  gmp_randinit_mt (rstate);
  (*func) ("gmp_randinit_mt", rstate);
  gmp_randclear (rstate);

  gmp_randinit_lc_2exp_size (rstate, 8L);
  (*func) ("gmp_randinit_lc_2exp_size 8", rstate);
  gmp_randclear (rstate);

  gmp_randinit_lc_2exp_size (rstate, 16L);
  (*func) ("gmp_randinit_lc_2exp_size 16", rstate);
  gmp_randclear (rstate);

  gmp_randinit_lc_2exp_size (rstate, 128L);
  (*func) ("gmp_randinit_lc_2exp_size 128", rstate);
  gmp_randclear (rstate);

  /* degenerate always zeros */
  mpz_set_ui (a, 0L);
  gmp_randinit_lc_2exp (rstate, a, 0L, 8L);
  (*func) ("gmp_randinit_lc_2exp a=0 c=0 m=8", rstate);
  gmp_randclear (rstate);

  /* degenerate always FFs */
  mpz_set_ui (a, 0L);
  gmp_randinit_lc_2exp (rstate, a, 0xFFL, 8L);
  (*func) ("gmp_randinit_lc_2exp a=0 c=0xFF m=8", rstate);
  gmp_randclear (rstate);

  mpz_clear (a);
}


/* Return +infinity if available, or 0 if not.
   We don't want to use libm, so INFINITY or other system values are not
   used here.  */
double
tests_infinity_d (void)
{
#if _GMP_IEEE_FLOATS
  union ieee_double_extract x;
  x.s.exp = 2047;
  x.s.manl = 0;
  x.s.manh = 0;
  x.s.sig = 0;
  return x.d;
#else
  return 0;
#endif
}


/* Return non-zero if d is an infinity (either positive or negative).
   Don't want libm, so don't use isinf() or other system tests.  */
int
tests_isinf (double d)
{
#if _GMP_IEEE_FLOATS
  union ieee_double_extract x;
  x.d = d;
  return (x.s.exp == 2047 && x.s.manl == 0 && x.s.manh == 0);
#else
  return 0;
#endif
}


/* Set the hardware floating point rounding mode.  Same mode values as mpfr,
   namely 0=nearest, 1=tozero, 2=up, 3=down.  Return 1 if successful, 0 if
   not.  */
int
tests_hardware_setround (int mode)
{
#if WANT_ASSEMBLY && HAVE_HOST_CPU_FAMILY_x86
  int  rc;
  switch (mode) {
  case 0: rc = 0; break;  /* nearest */
  case 1: rc = 3; break;  /* tozero  */
  case 2: rc = 2; break;  /* up      */
  case 3: rc = 1; break;  /* down    */
  default:
    return 0;
  }
  x86_fldcw ((x86_fstcw () & ~0xC00) | (rc << 10));
  return 1;
#endif

  return 0;
}

/* Return the hardware floating point rounding mode, or -1 if unknown. */
int
tests_hardware_getround (void)
{
#if WANT_ASSEMBLY && HAVE_HOST_CPU_FAMILY_x86
  switch ((x86_fstcw () & ~0xC00) >> 10) {
  case 0: return 0; break;  /* nearest */
  case 1: return 3; break;  /* down    */
  case 2: return 2; break;  /* up      */
  case 3: return 1; break;  /* tozero  */
  }
#endif

  return -1;
}


/* tests_dbl_mant_bits() determines by experiment the number of bits in the
   mantissa of a "double".  If it's not possible to find a value (perhaps
   due to the compiler optimizing too aggressively), then return 0.

   This code is used rather than DBL_MANT_DIG from <float.h> since ancient
   systems like SunOS don't have that file, and since one GNU/Linux ARM
   system was seen where the float emulation seemed to have only 32 working
   bits, not the 53 float.h claimed.  */

int
tests_dbl_mant_bits (void)
{
  static int n = -1;
  volatile double x, y, d;

  if (n != -1)
    return n;

  n = 1;
  x = 2.0;
  for (;;)
    {
      /* see if 2^(n+1)+1 can be formed without rounding, if so then
         continue, if not then "n" is the answer */
      y = x + 1.0;
      d = y - x;
      if (d != 1.0)
        {
#if defined (DBL_MANT_DIG) && DBL_RADIX == 2
          if (n != DBL_MANT_DIG)
            printf ("Warning, tests_dbl_mant_bits got %d but DBL_MANT_DIG says %d\n", n, DBL_MANT_DIG);
#endif
          break;
        }

      x *= 2;
      n++;

      if (n > 1000)
        {
          printf ("Oops, tests_dbl_mant_bits can't determine mantissa size\n");
          n = 0;
          break;
        }
    }
  return n;
}


/* See tests_setjmp_sigfpe in tests.h. */

jmp_buf    tests_sigfpe_target;

RETSIGTYPE
tests_sigfpe_handler (int sig)
{
  longjmp (tests_sigfpe_target, 1);
}

void
tests_sigfpe_done (void)
{
  signal (SIGFPE, SIG_DFL);
}
